I have much of the stuff mrsparky mentioned, and Andi3D's stuff is decent but I would KILL for a well done modern/dystopia style ruins set. Doesn't matter if it's city blocks or individual buildings that I could manipulate.

Alot of the images I like to do are post-apocalypse or future war related and it's a real pain to find well done models that can be used to achieve the whole effect without a lot of postwork. For instance imagine a scene with a hero fighting a monster, in or near a the shattered/chopped off ruin of an office building, and mid-scene you'd have some taller ruined buildings, and further back that ruined skyline that you see in almost all end of the world movies.

Not to mention there is a lack of tall buildings for a flyby or high up scene, with shattered office buildings missing their top floors, or smashed walls exposing the jagged frame, blown out windows ect.

Someday though... someday. :)